1. Field of the Invention
The present invention relates to a photosensitive device with a locally adjustable exposure time.
2. Description of the Prior Art
Photosensitive devices of the prior art are known whose exposure time is adjustable as a whole for the whole of the device. This is the case for example of the device described in the American U.S. Pat. No. 4,553,168.
These devices do not give entire satisfaction in numerous applications where the scenes analyzed comprise a high lighting dynamics.
This is the case for example when analyzing a landscape against the light or an opaque object against a light background.
In general either the light zone or the dark zone is favored, which causes a part of the information of the other zone to be lost.
For example, if the diaphragm of the lens is opened for analyzing a dark zone, the light zone then becomes saturated. The use of an anti-blooming device does not remove this problem, for, by clipping, it causes the loss of a part of the information corresponding to the light zone.
If on the other hand, the diaphragm is closed for analyzing a very light zone, the information from the dark zone is partially unusable.